Sofa



FIG. 1 is a front and right side perspective view of an exemplary sofa showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right side elevation view thereof, the left side being a mirror image; and,

FIG. 5 is a top plan view thereof. 

CLAIM The ornamental design for a sofa, as shown and described. 